it is most likely the main jet. take the bowl off the bottom of the carb and there will be a jet which just resembles a screw near the middle going strait into the main part of the carb. unscrew it and blow it with an airhose if you cant see through it, find a needle or something you can knock any junk out with and blow it out again just make sure you can see through the center of it and then put it back together
i had this issue, im not sure exactly why it does it, but i had to replace the trans.
look at the front of the motor and your see the nu 1 injector line on the right side of the head break the line loose and have someone turn the motor over tile the air bleeds out carful not to get the starter to hot and when the air is out it will fire right up but unless you ran it out of fuel or did something wronge putting in a new fuel fifter you may have a hole in the line some where
the regulator is in the gas tank
If your refurring to the fuel pump then yes, there is a gasket for it.